This invention relates to a hydraulic brake control device for a motor vehicle with an antilock brake control system or a traction control system. More specifically, this invention provides a hydraulic brake control device which improves a holding means for a coil unit of a solenoid valve.
A known hydraulic brake control device is an integral type device which comprises a hydraulic unit with a plural number of solenoid valves and an electronic control unit.
Each solenoid valve comprises a valve unit having the valve mechanism within a dome-shaped sleeve and a donut-shaped coil portion provided outside the valve unit. In order to assemble the solenoid valve, the valve unit is installed in a valve block of the hydraulic unit; the coil unit is installed in a cover of the electronic control unit; and the cover is assembled onto the valve block. This type of hydraulic brake control device is disclosed in the Japanese Opened Public Patent Application Number Heisei 7-215192.
In the above-described hydraulic brake control device, the coil unit is elastically supported between the top portion of the coil unit and the case via a spring material. A lead wire from the coil unit is extended through the lid portion of the case to be directly connected to the control board provided on the top surface of the case.
The above-described hydraulic brake control device has the following problems.
The hydraulic unit and the electronic control unit are individually manufactured and then assembled. The elastic effect of the spring becomes effective only after the coil unit is assembled on the valve block. Therefore, the coil unit is freely movable when transporting the electronic control unit with the coil unit before assembly with the hydraulic unit.
Accordingly, during transportation, the coil may move freely about which can apply a pulling force on the lead wire. In this manner, the electric connection of the lead wire may easily be broken.
Assembling the coil unit with or disassembling the coil unit from the valve unit can cause a compressive force or a pulling force on the lead wire, which could be a cause of breakage of the lead wire as well as breakage of the electric connection between the lead wire and the control board.
Thus, a special treatment must be done to provide a holding mechanism between the coil unit and the housing of the case during transport prior to assembly, which increases the cost of the device.